The present invention is directed to inspection of glassware articles such as glass containers, and more particularly to a method and apparatus for conveying articles of glassware through a series of inspection stations.
In the manufacture of glassware, such as glass containers, various anomalies or variations can occur that affect commercial acceptability of the containers. These anomalies, termed xe2x80x9ccommercial variations,xe2x80x9d can involve dimensional characteristics of the container such as at the container finish, surface characteristics that can affect acceptable operation of the container such as surface variations at the container sealing surface, or variations such as stones or checks within the container finish, sidewall or bottom. It is also conventional practice to mold indicia on each container indicative of the mold of origin of the container for inspection and quality control purposes. U.S. Pat. No. 4,378,493 illustrates a starwheel-type conveyor for accepting containers in sequence from an infeed conveyor and transporting the containers through a series of inspection stations. At at least some of the inspection stations, the container is held in position and rotated about its central axis while being electro-optically inspected for commercial variations and/or mold code. The term xe2x80x9cinspectionxe2x80x9d is used in its broadest sense to encompass any optical, electro-optical, mechanical or electrical observation or engagement with the container to measure or determine a potentially variable characteristic, including but not necessarily limited to mold codes and commercial variations.
It is a general object of the present invention to provide an apparatus and method for indexing articles of glassware such as glass containers through a series of stations, such as stations at which the containers are to be inspected for commercial variations and/or reading the mold of origin of the containers. Among more specific objects of the invention are to provide such a method and apparatus that are characterized by increased speed of conveyance and therefore increased throughput through the inspection stations, that are versatile and accommodate a wide variety of optical, electro-optical, electrical or mechanical inspection techniques at the individual stations, that accommodate an increased number of inspection stations, preferably including all necessary inspections in a single machine, that provide unobstructed view of the container for increased versatility of electro-optical inspection, and/or that accommodate containers of differing diameter and height.
Apparatus for indexing glassware such as containers through a series of stations, such as electro-optical or mechanical inspection stations, in accordance with a presently preferred embodiment of the invention includes first and second circumferential arrays of alternately opposed glassware gripping fingers mounted on associated first and second carriers. The carriers are rotatable on a common axis, with at least one of the carriers being rotatable with respect to the other for moving the fingers of the associated arrays toward and away from each other to grip and release glassware. The carriers are also rotatable conjointly about the common axis to transport each glassware article through the series of stations. In the preferred embodiment of the invention, each carrier is coupled to an associated motor for rotation independently with respect to each other and conjointly with each other about the common axis. The first carrier preferably overlies the second carrier and is coupled to its associated motor by a shaft that extends along the common axis. The second carrier preferably is coupled to its associated motor by a sleeve that surrounds the shaft.
Each carrier preferably comprises a central hub coupled to its associated motor and a peripheral portion on which the fingers are mounted. The peripheral portion of each carrier preferably includes an annular rim coupled to the associated hub and a plurality of ring segments removably mounted on the annular rim by quick-release locks. The ring segments have radially outwardly extending legs on which the fingers are mounted, with the legs on the first carrier being interdigitally disposed between the legs on the second carrier so that the fingers of each pair are angularly spaced from each other. The fingers of one array are mounted in fixed position on the associated carrier, while the fingers of the other array are resiliently biased toward the fingers of the one array for accommodating size variations among the articles of glassware. A layer of resilient material preferably is disposed on the glassware-engaging surface of each finger for resiliently engaging the glassware articles while reducing slippage of or damage to the articles.
A drive roller in the preferred embodiment of the invention is disposed for engaging and rotating an article of glassware at at least one of the stations, and a support pad and support roller are disposed at the station for supporting the article of glassware during rotation. A pair of angularly spaced back-up rollers are disposed adjacent to the support pad for holding the article in position while the article is rotated by the drive roller. The back-up rollers may be mounted for adjustment with respect to each other and with respect to the axis of rotation of the carriers for accommodating glassware articles of differing sizes. As an alternative, the back-up rollers may be mounted in fixed position on a roller support base, which may be replaceable for accommodating containers of differing diameter. The drive roller is coupled to an associated electric motor, and preferably is selectively pivotable into and out of engagement with a glassware article at the associated station.
A method of transporting glassware through a series of stations in accordance with a presently preferred embodiment of the invention contemplates providing first and second circumferential arrays of alternately opposed glassware gripping fingers, moving at least one of the arrays toward the other for simultaneously gripping articles of glassware at the stations, rotating the first and second arrays simultaneously on a common axis to index glassware between the stations, and then moving at least one of the arrays away from the other to release the articles of glassware at the stations. The stations preferably are disposed at equal angular increments around the common axis of rotation, and the steps of gripping, rotating and releasing the articles are repeated incrementally to convey the articles through the stations. An infeed conveyor preferably is located at one of the stations, and an outfeed conveyor is located at another of the stations for transporting containers to and from the apparatus of the invention. At at least one of the stations, each article of glassware in turn is inspected for commercial variations or for mold of origin.